Janis W-2 to Rythmik F12G ?

bdp24 · « **Reply #20 on:** 23 Feb 2014, 06:36 am »

Danny, aren't the actual nominal impedances of the three versions of the 8" woofers: 12 Ohms (OB version), 6 Ohms, and 3 Ohms?

Danny Richie · « **Reply #21 on:** 23 Feb 2014, 07:04 am »

Quote from: bdp24 on 23 Feb 2014, 06:36 am

Danny, aren't the actual nominal impedances of the three versions of the 8" woofers: 12 Ohms (OB version), 6 Ohms, and 3 Ohms?

The DCR or minimum impedance numbers are in those ranges.

wildberger · « **Reply #22 on:** 24 Feb 2014, 01:52 am »

How about another question: referencing the integration of the GR woofer in the Rythmik with the PEQ parametric version. What in preferable to run the Dynaudio speaker's full out & attempt to blend in using all the virtues of the PEQ?...or... use the rca in and out's...or experiment with both and decide what's best? Is there a theoretically best approach ie; keep filtering out when possible and reverting to the use of the filter when blending full range proves unsatisfactory? What is the approach that experienced pro's use when dealing with this circumstance? Is there reading on line concerning the above?
thanks for opinions

steve f · « **Reply #23 on:** 24 Feb 2014, 09:19 pm »

Some things to consider. What frequency do you plan to add the sub? If it's fairly low, like below 80 HZ, you are probably better off with the Rythmik version. If you plan on crossing over higher, use the GR version. Next, consider the number of subs used. Basically the more the merrier. Many use up to four subs, not for volume, but to eliminate room nodes. Then you don't need bass traps at all. If you can, use at least two of them. Then you have to decide if you are using flanking subs, running your mains full range, or rolling off the bass to your mains and letting the subs carry the low frequency load by themselves.
I feel like apologizing for making the issue more complex. The name of the game becomes one of room interaction. Both versions of the Rythmik/GR subs are excellent. Regards.

Steve

wildberger · « **Reply #24 on:** 24 Feb 2014, 11:01 pm »

The Dynaudio's are spec'd to go down to 48 +/- 3 db. I will experiment with 60 pass over. Is it true that...
" What frequency do you plan to add the sub? If it's fairly low, like below 80 HZ, you are probably better off with the Rythmik version. If you plan on crossing over higher, use the GR version. " ....
I'm ordering the GR version, in any case, because I believe that speed/weight issue is an important factor.
Is there something I am not aware of?

Danny Richie · « **Reply #25 on:** 24 Feb 2014, 11:22 pm »

Quote from: wildberger on 24 Feb 2014, 01:52 am

How about another question: referencing the integration of the GR woofer in the Rythmik with the PEQ parametric version. What in preferable to run the Dynaudio speaker's full out & attempt to blend in using all the virtues of the PEQ?...or... use the rca in and out's...or experiment with both and decide what's best? Is there a theoretically best approach ie; keep filtering out when possible and reverting to the use of the filter when blending full range proves unsatisfactory? What is the approach that experienced pro's use when dealing with this circumstance? Is there reading on line concerning the above?
thanks for opinions

I usually prefer to run the main speakers full range and then bring the subs in an need to create a smooth response.

The PEQ on the amp allows you to correct for a peak or dip in your room response. Ideally, you won't need it at all. But if you do have a problem then the EQ system will help.

When using this amp you really only want to use the RCA's "in" only. I don't recommend using the RCA "out" and running that to your main power amp.

If you need to drive your main speakers really hard and want to free up low end duty then you can do that with a high quality inline RCA filter.

Danny Richie · « **Reply #26 on:** 24 Feb 2014, 11:25 pm »

Quote from: steve f on 24 Feb 2014, 09:19 pm

Some things to consider. What frequency do you plan to add the sub? If it's fairly low, like below 80 HZ, you are probably better off with the Rythmik version. If you plan on crossing over higher, use the GR version.

Actually that isn't true.

If you are going to be beating on it to full X-max all the time and if it is just for movie effects then the Aluminum cone Rythmik driver might be for you.

If you are interested in higher detail levels and a more natural sound then the paper cone woofer will be better for you and sound better across the board regardless of high how you play it.

wildberger · « **Reply #27 on:** 25 Feb 2014, 12:19 am »

Danny, thanks for your reply above. I will run the mains in full range and work on blending
the Rythmik F12G in. I listen to music only and at moderate levels.
I look forward to hearing it soon!

bdp24 · « **Reply #28 on:** 25 Feb 2014, 12:12 pm »

Quote from: wildberger on 24 Feb 2014, 11:01 pm

The Dynaudio's are spec'd to go down to 48 +/- 3 db. I will experiment with 60 pass over. Is it true that...
" What frequency do you plan to add the sub? If it's fairly low, like below 80 HZ, you are probably better off with the Rythmik version. If you plan on crossing over higher, use the GR version. " ....
I'm ordering the GR version, in any case, because I believe that speed/weight issue is an important factor.
Is there something I am not aware of?

Danny recommends crossing over to his subs as low in frequency as possible, and to use the -6dB point of your main speakers' low frequency roll-off as your cross-over frequency. So in addition to the 60Hz point you're going to try, do so at 40Hz as well. If your speakers are sealed, their acoustic roll-off is second order (12dB/octave), which is also one of the low-pass filter settings on the Rythmik plate amp.

wildberger · « **Reply #29 on:** 8 Mar 2014, 01:03 pm »

Quote from: bdp24 on 25 Feb 2014, 12:12 pm

Danny recommends crossing over to his subs as low in frequency as possible, and to use the -6dB point of your main speakers' low frequency roll-off as your cross-over frequency. So in addition to the 60Hz point you're going to try, do so at 40Hz as well. If your speakers are sealed, their acoustic roll-off is second order (12dB/octave), which is also one of the low-pass filter settings on the Rythmik plate amp.

Thanks for this advice, though my speakers are ported, I am adjusting the 'blend in point' using my ears and a 'Radio Shack' sound level meter, as I now have the Rythmik F12G! and it has been a transformation of the lower bass in listening to music! Considering a second Rythmik to even out a null.

Question: I have been planning to do the Cabinet Mods and have 'dangerously?' thought that since I already have 1/2 inch MDF, I'd get some 1/4 inch cork board and 'nail' glue it between the inner wall and the MDF? Could this cause some unanticipated problems? Ringing? Given the inexpensive cost of MDF. I could easily get the 3/4 MDF. Already have the No Rez from Danny!
Could this be a break through? or stick with my day job.

walkern · « **Reply #30 on:** 8 Mar 2014, 03:29 pm »

You may want to try moving the sub around a bit (depending on room placement options) first to hear if you can eliminate or minimize your room null. I found that facing my sub (driver) away from the listening position and toward the back wall behind it helped tame a fairly audible room null at my listening position. Just a thought. Usually a second sub will solve such issues (again, so long as you have some flexibility about where you can place it), but sometimes slight position or orientation changes in your single sub will work wonders.

wildberger · « **Reply #31 on:** 8 Mar 2014, 03:47 pm »

Quote from: walkern on 8 Mar 2014, 03:29 pm

You may want to try moving the sub around a bit (depending on room placement options) first to hear if you can eliminate or minimize your room null. I found that facing my sub (driver) away from the listening position and toward the back wall behind it helped tame a fairly audible room null at my listening position. Just a thought. Usually a second sub will solve such issues (again, so long as you have some flexibility about where you can place it), but sometimes slight position or orientation changes in your single sub will work wonders.

Thanks you for sharing your experience. The room null is around 40 hz. I do have the flexibility to try moving the sub around and will. Trying to do as few changes at a time as possible, so I can experience the cause and effect.

Captainhemo · « **Reply #32 on:** 8 Mar 2014, 07:25 pm »

Quote from: wildberger on 8 Mar 2014, 01:03 pm

Thanks for this advice, though my speakers are ported, I am adjusting the 'blend in point' using my ears and a 'Radio Shack' sound level meter, as I now have the Rythmik F12G! and it has been a transformation of the lower bass in listening to music! Considering a second Rythmik to even out a null.

Question: I have been planning to do the Cabinet Mods and have 'dangerously?' thought that since I already have 1/2 inch MDF, I'd get some 1/4 inch cork board and 'nail' glue it between the inner wall and the MDF? Could this cause some unanticipated problems? Ringing? Given the inexpensive cost of MDF. I could easily get the 3/4 MDF. Already have the No Rez from Danny!
Could this be a break through? or stick with my day job.

I would either use only the 1/" MDF or go get a half sheet of the 3/4" MDF and skip putting any cork in between. Then, I'd get a sheet of no-rez from Danny and cover the new layer of MDF you put in ( I'm assuming that the sub didn't come with no-rez? but I am not sure).

-jay

bdp24 · « **Reply #33 on:** 9 Mar 2014, 06:30 pm »

Quote from: wildberger on 8 Mar 2014, 01:03 pm

Thanks for this advice, though my speakers are ported, I am adjusting the 'blend in point' using my ears and a 'Radio Shack' sound level meter, as I now have the Rythmik F12G! and it has been a transformation of the lower bass in listening to music! Considering a second Rythmik to even out a null.

Question: I have been planning to do the Cabinet Mods and have 'dangerously?' thought that since I already have 1/2 inch MDF, I'd get some 1/4 inch cork board and 'nail' glue it between the inner wall and the MDF? Could this cause some unanticipated problems? Ringing? Given the inexpensive cost of MDF. I could easily get the 3/4 MDF. Already have the No Rez from Danny!
Could this be a break through? or stick with my day job.

Even better than cork would be some of the 1/8" mass-loaded vinyl made for constrained-layer damping. Do a Google search and a bunch of it will come up, from a few different companies. It's all basically the same. Put one layer of it between two layers of MDF.

wildberger · « **Reply #34 on:** 9 Mar 2014, 07:04 pm »

Even better than cork would be some of the 1/8" mass-loaded vinyl made for constrained-layer damping. Do a Google search and a bunch of it will come up, from a few different companies. It's all basically the same. Put one layer of it between two layers of MDF.

Great idea, I think! I'll check it out! I believe Danny would approve.
Thanks.

Captainhemo · « **Reply #35 on:** 9 Mar 2014, 07:17 pm »

Are you talking about putting this between the inner and outer layers of MDF (that's how I read your original idea)?
Not sure I see the point if so, Glue/screw the layers of MDF togther so you have 1 soldi piece then put your dampening material on top

That heavy vinyl will work, even better add a layer of 1" open cell foam over it. Better yet, kike I mentioned earlier, just buy some no-rez. Easy to cut and no screwing around with adhesives and will do a better job thanthe vinyl/foam

-jay

wildberger · « **Reply #36 on:** 9 Mar 2014, 07:37 pm »

Quote from: Captainhemo on 9 Mar 2014, 07:17 pm

Are you talking about putting this between the inner and outer layers of MDF (that's how I read your original idea)?
Not sure I see the point if so, Glue/screw the layers of MDF togther so you have 1 soldi piece then put your dampening material on top

That heavy vinyl will work, even better add a layer of 1" open cell foam over it. Better yet, kike I mentioned earlier, just buy some no-rez. Easy to cut and no screwing around with adhesives and will do a better job thanthe vinyl/foam

-jay

OK, I don't have the experience to know which way is best? I suppose either way will improve the sub. Already have a sheet of 'no rez'.
Thanks for offering your opinion.

Captainhemo · « **Reply #37 on:** 9 Mar 2014, 07:57 pm »

I've done both mothods , vinyl and OCF vs No-Rez. The no rez is easier and works better.
There is a thread regarding this in Danny's circle , I just can't remember where

-jay

wildberger · « **Reply #38 on:** 9 Mar 2014, 08:35 pm »

Quote from: Captainhemo on 9 Mar 2014, 07:57 pm

I've done both mothods , vinyl and OCF vs No-Rez. The no rez is easier and works better.
There is a thread regarding this in Danny's circle , I just can't remember where

-jay

The question, as I understand it is where to put the 'mass-loaded vinyl '. I have the 'no rez' and plan to use it last. I have already 1/2" MDF, which I plan to use. Question is whether to use 'mass-loaded vinyl' where? or if at all?

Thanks

Danny Richie · « **Reply #39 on:** 9 Mar 2014, 08:45 pm »

If you are building the box from scratch then sandwiching a vinyl layer works great, but both inner and outer walls are secured on all sides. So you make a solid sheet with a varied density inside.

In this case the box is already built and there are some little corner braces in there to work around. So I'd glue in another layer of 3/4" MDF in little pieces hitting braces and outer walls where you can. Then add a layer of your heavy vinyl on top of it to help damp it.